Like the detectives on the CBS drama Cold Case, anthropologist Ann H. Ross of North Carolina State University spends many of her days thinking about unsolved crimes. Her most recent work has aimed at developing software that helps forensic scientists determine the sex and ancestry of modern ­human skulls.

Typically forensic scientists measure remains with sliding rulers called calipers. Doing so results in two-dimensional measurements. Ross’s software, called 3D-ID and developed with a grant from the U.S. Department of Justice, relies on three-dimensional measurements that scientists take with a digitizer—a computer and stylus. “The stylus allows you to place the coordinates in real space, so you get a better idea of the actual biological form of whatever you’re measuring,” Ross says.